After uptae driver and app, Acer aspire e1-421 webcam stilldoes not work. But online test on webcam is ok.

How did you update the driver and what app are you talking about? Has it ever worked? When did it stop and what happened before it stopped if anything? What online test are you talking about, you can actually see an image using the webcam on something like Skype? In what way does it not work then?